The quantification of zinc in the mucosal cells of human small intestine using x-ray microanalysis

The intracellular zinc concentration of human small intestinal mucosal cells was estimated using X-ray microanalysis. Jejunum and ileum from 11 patients resected during surgery was fixed in 2.5% glutaraldehyde and acetone and the estimations performed with an AEI EMMA 4. The zinc content of undifferentiated stem cells, enterocytes, goblet cells and Paneth cells was determined and all the cell types were found to contain significant amounts of zinc. The highest levels were found in the stem cells and enterocytes with a maximum in the ideal enterocytes in Crohn's disease. In non-inflammatory conditions the ileal enterocytes had a zinc content than the jejunal enterocytes. Stem cells had comparable levels in all tissues analysed. Goblet cells showed a wide variation in zinc levels that may be due to their secretory status. Paneth cells had the lowest zinc levels. The whole Paneth cell zinc and granule zinc were of the same order in all tissues sampled. The cytoplasmic zinc was higher than the granule zinc in all samples of ileum analysed, but was no significant difference in the jejunum. The limitations of the technique are considered and observations made on the role of zinc in intestinal mucosa.